A rugged, largely snow-covered massif 27 mi long, standing W of the Forrestal Range in the N part of the Pensacola Mountains. Discovered and photographed on Jan. 13, 1956 on a transcontinental patrol plane flight of U.S. Navy Operation Deep Freeze I from McMurdo Sound to the vicinity of Weddell Sea and return, and named by the US-ACAN for R. Admiral George J. Dufek, USN (Dufek Coast, q.v.), in direct operational command of U.S. Navy Task Force 43 during that operation. The entire Pensacola Mountains were mapped by USGS in 1967 and 1968 from ground surveys and U.S. Navy tricamera aerial photographs taken in 1964.